// This code is derived from jcifs smb client library <jcifs at samba dot org>
// Ported by J. Arturo <webmaster at komodosoft dot net>
//  
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
using System;
using System.IO;

namespace SharpCifs.Util
{
    public class Hexdump
    {
        private static readonly int NlLength = Environment.NewLine.Length;

        private static readonly char[] SpaceChars = 
        {
            ' ', ' ', ' ', ' ', ' '
            , ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '
            , ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '
            , ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '
        };

        public static readonly char[] HexDigits 
            = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };


        private static bool IsIsoControl(char c)
        {
            return (c >= '\u0000' && c <= '\u001F') || (c >= '\u007F' && c <= '\u009F');
        }

        /// <summary>
        /// Generate "hexdump" output of the buffer at src like the following:
        /// <p><blockquote><pre>
        /// 00000: 04 d2 29 00 00 01 00 00 00 00 00 01 20 45 47 46  |..).........
        /// </summary>
        /// <remarks>
        /// Generate "hexdump" output of the buffer at src like the following:
        /// <p><blockquote><pre>
        /// 00000: 04 d2 29 00 00 01 00 00 00 00 00 01 20 45 47 46  |..)......... EGF|
        /// 00010: 43 45 46 45 45 43 41 43 41 43 41 43 41 43 41 43  |CEFEECACACACACAC|
        /// 00020: 41 43 41 43 41 43 41 43 41 43 41 41 44 00 00 20  |ACACACACACAAD.. |
        /// 00030: 00 01 c0 0c 00 20 00 01 00 00 00 00 00 06 20 00  |..... ........ .|
        /// 00040: ac 22 22 e1                                      |."".            |
        /// </blockquote></pre>
        /// </remarks>
        public static void ToHexdump(TextWriter ps, byte[] src, int srcIndex, int length)
        {
            if (length == 0)
            {
                return;
            }
            int s = length % 16;
            int r = (length + 15) / 16;
            char[] c = new char[r * (74 + NlLength)];
            char[] d = new char[16];
            int i;
            int si = 0;
            int ci = 0;
            do
            {
                ToHexChars(si, c, ci, 5);
                ci += 5;
                c[ci++] = ':';
                do
                {
                    if (si == length)
                    {
                        int n = 16 - s;
                        Array.Copy(SpaceChars, 0, c, ci, n * 3);
                        ci += n * 3;
                        Array.Copy(SpaceChars, 0, d, s, n);
                        break;
                    }
                    c[ci++] = ' ';
                    i = src[srcIndex + si] & 0xFF;
                    ToHexChars(i, c, ci, 2);
                    ci += 2;
                    if (i < 0 || IsIsoControl((char)i))
                    {
                        d[si % 16] = '.';
                    }
                    else
                    {
                        d[si % 16] = (char)i;
                    }
                }
                while ((++si % 16) != 0);
                c[ci++] = ' ';
                c[ci++] = ' ';
                c[ci++] = '|';
                Array.Copy(d, 0, c, ci, 16);
                ci += 16;
                c[ci++] = '|';
                //Sharpen.Runtime.GetCharsForString(NL, 0, NL_LENGTH, c, ci);
                Array.Copy(Environment.NewLine.ToCharArray(0, NlLength), 0, c, ci, NlLength);
                ci += NlLength;
            }
            while (si < length);
            ps.WriteLine(c);
        }

        /// <summary>
        /// This is an alternative to the <code>java.lang.Integer.toHexString</cod>
        /// method.
        /// </summary>
        /// <remarks>
        /// This is an alternative to the <code>java.lang.Integer.toHexString</cod>
        /// method. It is an efficient relative that also will pad the left side so
        /// that the result is <code>size</code> digits.
        /// </remarks>
        public static string ToHexString(int val, int size)
        {
            char[] c = new char[size];
            ToHexChars(val, c, 0, size);
            return new string(c);
        }

        public static string ToHexString(long val, int size)
        {
            char[] c = new char[size];
            ToHexChars(val, c, 0, size);
            return new string(c);
        }

        public static string ToHexString(byte[] src, int srcIndex, int size)
        {
            char[] c = new char[size];
            size = (size % 2 == 0) ? size / 2 : size / 2 + 1;
            for (int i = 0, j = 0; i < size; i++)
            {
                c[j++] = HexDigits[(src[i] >> 4) & 0x0F];
                if (j == c.Length)
                {
                    break;
                }
                c[j++] = HexDigits[src[i] & 0x0F];
            }
            return new string(c);
        }

        /// <summary>
        /// This is the same as
        /// <see cref="ToHexString(int, int)">ToHexString(int, int)</see>
        /// but provides a more practical form when trying to avoid
        /// <see cref="string">string</see>
        /// concatenation and
        /// <see cref="System.Text.StringBuilder">System.Text.StringBuilder</see>
        /// .
        /// </summary>
        public static void ToHexChars(int val, char[] dst, int dstIndex, int size)
        {
            while (size > 0)
            {
                int i = dstIndex + size - 1;
                if (i < dst.Length)
                {
                    dst[i] = HexDigits[val & 0x000F];
                }
                if (val != 0)
                {
                    val = (int)(((uint)val) >> 4);
                }
                size--;
            }
        }

        public static void ToHexChars(long val, char[] dst, int dstIndex, int size)
        {
            while (size > 0)
            {
                dst[dstIndex + size - 1] = HexDigits[(int)(val & 0x000FL)];
                if (val != 0)
                {
                    val = (long)(((ulong)val) >> 4);
                }
                size--;
            }
        }
    }
}
